<?php 
require('include/book.php');
require('include/authority.php');
if(!Authority::is_manager())
  {
    die('FAIL');
  }
$ID = $_GET['ID'];
if(!isset($ID))
  {
    die('FAIL');
  }
if (!Book::del_book_by_ID($ID))
  {
    die('FAIL');
  }
die('OK');
?>